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For a random variable $X, E(X)=3 $ and $E(X^2)=11.$ Then value of Var(2X) is : |
8 5 4 2 |
8 |
The correct answer is Option (1) → 8 $E(X)=3$ $E(X^2)=11$ $Var(X)=E(X^2)-[E(X)]^2$ $=11-3^2=2$ $⇒Var(aX)=a^2Var(X)$ $⇒Var(2X)=2^2Var(X)=2^3=8$ |
